About duplicate penalty - spun articles
I think that GSA users who use spun articles with article/web 2/wiki engine types may be interested about this discussion.
By the past, i have been "penalized" because i subscribed to a directory submission service that submitted the exact same title and text 100 times. I did that twice over two of my domains.
On the very same day, i had a drop in traffic. Actually, i understood what happened. Google stopped to count those backlinks Urls. So google did not penalize my website but it penalized the directories where there were a title/text and link to my website.
In other words, in the worst case scenario, if something goes wrong with the spun articles submission, you may lose the google juice from those created URL by GSA but your website is NOT going to be banned or penalized.
That's why you should also consider creating manual blogs and send non contextual Tier 2 links to those manual blogs.
Bottom line:
I don't believe in the negative SEO. Googlebot is just made of algorithms and it is not black magic.